Direct answer. In PrintExactly, enter the image width and height in mm, cm, or inches, place it on a sheet that matches the loaded paper, review the printable area, then check driver-specific scaling in the macOS print panel.

The 3-step method

  1. Pick the paper and the active printer. PrintExactly sizes the document to match the loaded paper and reads the active Mac printer's printable area before you start.
  2. Enter the image dimensions in any unit. Type the target width and height in mm, cm, or inches. Common photo, ID, and frame sizes are presets, but every value is editable to the millimeter.
  3. Check effective DPI, printable area, and print settings. PrintExactly surfaces effective DPI, flags clipping, and prints the generated PDF without page scaling. Review driver-specific scaling before printing.

Why an image prints the wrong size on Mac

  • Scale to Fit shrinks the image. The macOS print dialog scales the image to fill the loaded paper. Turn off Scale to Fit and set Scale to 100%.
  • Pixel size confusion. An image's pixel dimensions are not the printed size. Set mm, cm, or inches in PrintExactly; check effective DPI to confirm the source is high enough resolution.

Frequently asked questions

What is the difference between Content size and Frame size?

Image Content is measured in pixels (for example, 4000 × 3000). A Photo Frame is measured in physical units (for example, 4 × 6 inches). PrintExactly sizes the Frame in mm, cm, or inches and reports effective DPI from the Content's pixel count.

Will the image actually print at 100%?

PrintExactly prints its generated PDF without page scaling. The measured result still depends on matching paper, turning off fit-to-page and driver scaling, avoiding borderless expansion, and the printer's physical tolerance.

Print a photo at exact size on Mac · Full exact-size Mac guide